<!DOCTYPE html>



  


<html class="theme-next pisces use-motion" lang="zh-Hans">
<head><meta name="generator" content="Hexo 3.8.0">
  <meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1">
<meta name="theme-color" content="#222">



  
  
    
    
  <script src="/lib/pace/pace.min.js?v=1.0.2"></script>
  <link href="/lib/pace/pace-theme-minimal.min.css?v=1.0.2" rel="stylesheet">







<meta http-equiv="Cache-Control" content="no-transform">
<meta http-equiv="Cache-Control" content="no-siteapp">
















  
  
  <link href="/lib/fancybox/source/jquery.fancybox.css?v=2.1.5" rel="stylesheet" type="text/css">







<link href="/lib/font-awesome/css/font-awesome.min.css?v=4.6.2" rel="stylesheet" type="text/css">

<link href="/css/main.css?v=5.1.4" rel="stylesheet" type="text/css">



  <link rel="icon" type="image/png" sizes="32x32" href="/images/favicon-32x32.ico?v=5.1.4">


  <link rel="icon" type="image/png" sizes="16x16" href="/images/favicon-16x16.ico?v=5.1.4">






  <meta name="keywords" content="Hexo, NexT">










<meta name="description" content="待解决dataclass + __solts__的问题  github上相关问题 多加一个装饰器 基础1234567891011121314151617181920212223class Color():    r = 200    def __init__(self,r=250):        self.r = r        self.g = self.get_g()        sel">
<meta property="og:type" content="article">
<meta property="og:title" content="面向对象">
<meta property="og:url" content="http://imwl.ml/python练习/面向对象/index.html">
<meta property="og:site_name" content="Get busy living">
<meta property="og:description" content="待解决dataclass + __solts__的问题  github上相关问题 多加一个装饰器 基础1234567891011121314151617181920212223class Color():    r = 200    def __init__(self,r=250):        self.r = r        self.g = self.get_g()        sel">
<meta property="og:locale" content="zh-Hans">
<meta property="og:updated_time" content="2019-07-17T12:20:22.000Z">
<meta name="twitter:card" content="summary">
<meta name="twitter:title" content="面向对象">
<meta name="twitter:description" content="待解决dataclass + __solts__的问题  github上相关问题 多加一个装饰器 基础1234567891011121314151617181920212223class Color():    r = 200    def __init__(self,r=250):        self.r = r        self.g = self.get_g()        sel">



<script type="text/javascript" id="hexo.configurations">
  var NexT = window.NexT || {};
  var CONFIG = {
    root: '/',
    scheme: 'Pisces',
    version: '5.1.4',
    sidebar: {"position":"right","display":"post","offset":12,"b2t":false,"scrollpercent":false,"onmobile":false},
    fancybox: true,
    tabs: true,
    motion: {"enable":true,"async":false,"transition":{"post_block":"fadeIn","post_header":"slideDownIn","post_body":"slideDownIn","coll_header":"slideLeftIn","sidebar":"slideUpIn"}},
    duoshuo: {
      userId: '0',
      author: '博主'
    },
    algolia: {
      applicationID: '',
      apiKey: '',
      indexName: '',
      hits: {"per_page":10},
      labels: {"input_placeholder":"Search for Posts","hits_empty":"We didn't find any results for the search: ${query}","hits_stats":"${hits} results found in ${time} ms"}
    }
  };
</script>



  <link rel="canonical" href="http://imwl.ml/python练习/面向对象/">





  <title>面向对象 | Get busy living</title>
  








</head>

<body itemscope="" itemtype="http://schema.org/WebPage" lang="zh-Hans">

  
  
    
  

  <div class="container sidebar-position-right page-post-detail">
    <div class="headband"></div>
	

    <header id="header" class="header" itemscope="" itemtype="http://schema.org/WPHeader">
      <div class="header-inner"><div class="site-brand-wrapper">
  <div class="site-meta ">
    

    <div class="custom-logo-site-title">
      <a href="/" class="brand" rel="start">
        <span class="logo-line-before"><i></i></span>
        <span class="site-title">Get busy living</span>
        <span class="logo-line-after"><i></i></span>
      </a>
    </div>
      
        <p class="site-subtitle">Stay Hungry,Stay Foolish</p>
      
  </div>

  <div class="site-nav-toggle">
    <button>
      <span class="btn-bar"></span>
      <span class="btn-bar"></span>
      <span class="btn-bar"></span>
    </button>
  </div>
</div>

<nav class="site-nav">
  

  
    <ul id="menu" class="menu">
      
        
        <li class="menu-item menu-item-home">
          <a href="/" rel="section">
            
              <i class="menu-item-icon fa fa-fw fa-home"></i> <br>
            
            首页
          </a>
        </li>
      
        
        <li class="menu-item menu-item-categories">
          <a href="/categories/" rel="section">
            
              <i class="menu-item-icon fa fa-fw fa-th"></i> <br>
            
            分类
          </a>
        </li>
      
        
        <li class="menu-item menu-item-archives">
          <a href="/archives/" rel="section">
            
              <i class="menu-item-icon fa fa-fw fa-archive"></i> <br>
            
            归档
          </a>
        </li>
      
        
        <li class="menu-item menu-item-gitbook">
          <a href="/book/" rel="section">
            
              <i class="menu-item-icon fa fa-fw fa-book"></i> <br>
            
            gitbook
          </a>
        </li>
      
        
        <li class="menu-item menu-item-resume">
          <a href="/resume/" rel="section">
            
              <i class="menu-item-icon fa fa-fw fa-address-card"></i> <br>
            
            个人简历
          </a>
        </li>
      
        
        <li class="menu-item menu-item-about">
          <a href="/about/" rel="section">
            
              <i class="menu-item-icon fa fa-fw fa-user"></i> <br>
            
            关于
          </a>
        </li>
      

      
        <li class="menu-item menu-item-search">
          
            <a href="javascript:;" class="popup-trigger">
          
            
              <i class="menu-item-icon fa fa-search fa-fw"></i> <br>
            
            搜索
          </a>
        </li>
      
    </ul>
  

  
    <div class="site-search">
      
  <div class="popup search-popup local-search-popup">
  <div class="local-search-header clearfix">
    <span class="search-icon">
      <i class="fa fa-search"></i>
    </span>
    <span class="popup-btn-close">
      <i class="fa fa-times-circle"></i>
    </span>
    <div class="local-search-input-wrapper">
      <input autocomplete="off" placeholder="搜索..." spellcheck="false" type="text" id="local-search-input">
    </div>
  </div>
  <div id="local-search-result"></div>
</div>



    </div>
  
</nav>



 </div>
    </header>

    <main id="main" class="main">
      <div class="main-inner">
        <div class="content-wrap">
          <div id="content" class="content">
            

  <div id="posts" class="posts-expand">
    

  

  
  
  

  <article class="post post-type-normal" itemscope="" itemtype="http://schema.org/Article">
  
  
  
  <div class="post-block">
    <link itemprop="mainEntityOfPage" href="http://imwl.ml/python练习/面向对象/">

    <span hidden itemprop="author" itemscope="" itemtype="http://schema.org/Person">
      <meta itemprop="name" content="WeiLai">
      <meta itemprop="description" content="">
      <meta itemprop="image" content="/images/avatar.png">
    </span>

    <span hidden itemprop="publisher" itemscope="" itemtype="http://schema.org/Organization">
      <meta itemprop="name" content="Get busy living">
    </span>

    
      <header class="post-header">

        
        
          <h1 class="post-title" itemprop="name headline">面向对象</h1>
        

        <div class="post-meta">
          <span class="post-time">
            
              <span class="post-meta-item-icon">
                <i class="fa fa-calendar-o"></i>
              </span>
              
                <span class="post-meta-item-text">发表于</span>
              
              <time title="创建于" itemprop="dateCreated datePublished" datetime="2019-07-15T11:05:31+08:00">
                2019-07-15
              </time>
            

            

            
          </span>

          
            <span class="post-category">
            
              <span class="post-meta-divider">|</span>
            
              <span class="post-meta-item-icon">
                <i class="fa fa-folder-o"></i>
              </span>
              
                <span class="post-meta-item-text">分类于</span>
              
              
                <span itemprop="about" itemscope="" itemtype="http://schema.org/Thing">
                  <a href="/categories/python练习/" itemprop="url" rel="index">
                    <span itemprop="name">python练习</span>
                  </a>
                </span>

                
                
              
            </span>
          

          
            
          

          
          

          

          

          

        </div>
      </header>
    

    
    
    
    <div class="post-body" itemprop="articleBody">

      
      

      
        <h1 id="待解决"><a href="#待解决" class="headerlink" title="待解决"></a>待解决</h1><p><code>dataclass</code> + <code>__solts__</code>的问题 </p>
<p><a href="https://github.com/ericvsmith/dataclasses/issues/28" target="_blank" rel="noopener">github上相关问题</a></p>
<p><a href="https://github.com/ericvsmith/dataclasses/blob/master/dataclass_tools.py" target="_blank" rel="noopener">多加一个装饰器</a></p>
<h2 id="基础"><a href="#基础" class="headerlink" title="基础"></a>基础</h2><figure class="highlight plain"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br></pre></td><td class="code"><pre><span class="line">class Color():</span><br><span class="line">    r = 200</span><br><span class="line">    def __init__(self,r=250):</span><br><span class="line">        self.r = r</span><br><span class="line">        self.g = self.get_g()</span><br><span class="line">        self.b = self.get_b</span><br><span class="line"></span><br><span class="line">    def get_g(self):</span><br><span class="line">        g = 223</span><br><span class="line">        return g</span><br><span class="line"></span><br><span class="line">    @property</span><br><span class="line">    def get_b(self):</span><br><span class="line">        b = 222</span><br><span class="line">        return b</span><br><span class="line"></span><br><span class="line">    def __str__(self):</span><br><span class="line">        return  f&apos;&#123;self.__class__.__name__&#125;(class_r = &#123;self.__class__.r&#125;, r = &#123;self.r&#125;, g = &#123;self.g&#125;, b = &#123;self.b&#125;)&apos;</span><br><span class="line"></span><br><span class="line">color = Color(255)</span><br><span class="line">color1 = Color()</span><br><span class="line">print(color)  #  Color(class_r = 200, r = 255, g = 223, b = 222)</span><br><span class="line">print(color1)  # Color(class_r = 200, r = 250, g = 223, b = 222)</span><br></pre></td></tr></table></figure>
<figure class="highlight plain"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br></pre></td><td class="code"><pre><span class="line">class Color():</span><br><span class="line">    r = 200</span><br><span class="line">    def __init__(self):</span><br><span class="line">        self.g = self.get_g()</span><br><span class="line">        self.b = self.get_b</span><br><span class="line"></span><br><span class="line">    def get_g(self):</span><br><span class="line">        g = 223</span><br><span class="line">        return g</span><br><span class="line"></span><br><span class="line">    @property</span><br><span class="line">    def get_b(self):</span><br><span class="line">        b = 222</span><br><span class="line">        return b</span><br><span class="line"></span><br><span class="line">    def __str__(self):</span><br><span class="line">        return  f&apos;&#123;self.__class__.__name__&#125;(class_r = &#123;self.__class__.r&#125;, r = &#123;self.r&#125;, g = &#123;self.g&#125;, b = &#123;self.b&#125;)&apos;</span><br><span class="line"></span><br><span class="line">color = Color()</span><br><span class="line">print(color)  #  Color(class_r = 200, r = 255, g = 223, b = 222)</span><br></pre></td></tr></table></figure>
<h2 id="使用第三方插件修改一下"><a href="#使用第三方插件修改一下" class="headerlink" title="使用第三方插件修改一下"></a>使用第三方插件修改一下</h2><figure class="highlight plain"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br></pre></td><td class="code"><pre><span class="line">from attr import attrs, attrib  # dataclass 内置库可替代</span><br><span class="line">&apos;&apos;&apos;</span><br><span class="line">attrs 修饰符，可以自动实现__init__,__repr__,__eq__,__ne__,__it__,__le__,__gt__,</span><br><span class="line">__ge__,__hash__,这几个方法</span><br><span class="line">&apos;&apos;&apos;</span><br><span class="line"></span><br><span class="line">@attrs</span><br><span class="line">class Color():</span><br><span class="line">    r = attrib(type=int, default=100)</span><br><span class="line">    g = attrib(type=int, default=200)</span><br><span class="line">    b = attrib(type=int, default=222)</span><br><span class="line"></span><br><span class="line"></span><br><span class="line">color = Color(255,254,253)</span><br><span class="line">color1 = Color()</span><br><span class="line">print(color)  #  Color(class_r = 200, r = 255, g = 223, b = 222)</span><br><span class="line">print(color1)  # Color(class_r = 200, r = 250, g = 223, b = 222)</span><br></pre></td></tr></table></figure>
<h2 id="声明和比较"><a href="#声明和比较" class="headerlink" title="声明和比较"></a>声明和比较</h2><figure class="highlight plain"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br></pre></td><td class="code"><pre><span class="line">from attr import attrs, attrib  # dataclass内置库可替代</span><br><span class="line"></span><br><span class="line">&apos;&apos;&apos;</span><br><span class="line">attrs 修饰符，可以自动实现__init__,__repr__,__eq__,__ne__,__it__,__le__,__gt__,</span><br><span class="line">__ge__,__hash__,这几个方法</span><br><span class="line">&apos;&apos;&apos;</span><br><span class="line"></span><br><span class="line">@attrs</span><br><span class="line">class Point():</span><br><span class="line">    x = attrib()</span><br><span class="line">    y = attrib()</span><br><span class="line"></span><br><span class="line">p1 = Point(1,2)</span><br><span class="line">p2 = Point(y=3,x=4)</span><br><span class="line">print(p1,p2)  # Point(x=1, y=2) Point(x=4, y=3)</span><br></pre></td></tr></table></figure>
<h2 id="使用python3-7-的内置库"><a href="#使用python3-7-的内置库" class="headerlink" title="使用python3.7 的内置库"></a>使用python3.7 的内置库</h2><figure class="highlight plain"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br></pre></td><td class="code"><pre><span class="line">from dataclasses import dataclass</span><br><span class="line"></span><br><span class="line">@dataclass</span><br><span class="line">class Point():</span><br><span class="line">    x:int = 0</span><br><span class="line">    y:int = 0</span><br><span class="line"></span><br><span class="line">p1 = Point(1,2)</span><br><span class="line">p2 = Point(y=3,x=4)</span><br><span class="line">print(p1,p2)  # Point(x=1, y=2) Point(x=4, y=3)</span><br></pre></td></tr></table></figure>
<figure class="highlight plain"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br></pre></td><td class="code"><pre><span class="line"># 默认init,repr,eq 为True， 其余为False</span><br><span class="line">@dataclass(init=1,repr=1,eq=1,order=1,unsafe_hash=0,frozen=0)</span><br><span class="line">class Point():</span><br><span class="line">    x:int = 0</span><br><span class="line">    y:int = 0</span><br><span class="line"></span><br><span class="line">p1 = Point(1,2)</span><br><span class="line">p2 = Point(y=3,x=4)</span><br><span class="line">p3 = Point(x=1,y=2)</span><br><span class="line">print(p1&gt;p2)  # fasle</span><br><span class="line">print(p1==p3)  # True</span><br></pre></td></tr></table></figure>
<figure class="highlight plain"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br></pre></td><td class="code"><pre><span class="line">from dataclasses import dataclass</span><br><span class="line"></span><br><span class="line">@dataclass(frozen=1)</span><br><span class="line">class Point():</span><br><span class="line">    x:int = 0</span><br><span class="line">    y:int = 0</span><br><span class="line"></span><br><span class="line">p1 = Point(1,2)</span><br><span class="line">print(p1)  </span><br><span class="line"># 当实例化一个frozen 对象时，任何企图修改对象属性的行为都会引发 FrozenInstanceError</span><br><span class="line">#p1.x = 10  # dataclasses.FrozenInstanceError: cannot assign to field &apos;x&apos;</span><br></pre></td></tr></table></figure>
<figure class="highlight plain"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br></pre></td><td class="code"><pre><span class="line">from dataclasses import dataclass</span><br><span class="line"></span><br><span class="line">@dataclass()</span><br><span class="line">class Point():</span><br><span class="line">    x:int = 0</span><br><span class="line">    y:int = 0</span><br><span class="line"></span><br><span class="line">    def x_add_1(self):</span><br><span class="line">        self.x += 1</span><br><span class="line"></span><br><span class="line">p1 = Point(1,2)</span><br><span class="line">print(p1)  # Point(x=1, y=2)</span><br><span class="line">p1.x_add_1()</span><br><span class="line">print(p1)  # Point(x=2, y=2)</span><br></pre></td></tr></table></figure>
<p><code>__init__</code>方法在返回前会调用<code>__post_init__</code><br><figure class="highlight plain"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br></pre></td><td class="code"><pre><span class="line">from dataclasses import dataclass</span><br><span class="line"></span><br><span class="line">@dataclass()</span><br><span class="line">class Point():</span><br><span class="line">    x:int = 0</span><br><span class="line">    y:int = 0</span><br><span class="line"></span><br><span class="line">    def __post_init__(self):</span><br><span class="line">        self.x += 1</span><br><span class="line">        </span><br><span class="line">p1 = Point(1,2)</span><br><span class="line">print(p1)  # Point(x=2, y=2)</span><br></pre></td></tr></table></figure></p>
<h3 id="有关继承"><a href="#有关继承" class="headerlink" title="有关继承"></a>有关继承</h3><figure class="highlight plain"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br></pre></td><td class="code"><pre><span class="line">from dataclasses import dataclass</span><br><span class="line"></span><br><span class="line">@dataclass</span><br><span class="line">class Point:</span><br><span class="line">    x:int = 0</span><br><span class="line">    y:int = 0</span><br><span class="line"></span><br><span class="line">    def __post_init__(self):</span><br><span class="line">        self.x += 1</span><br><span class="line"></span><br><span class="line">@dataclass</span><br><span class="line">class ThirdPonit(Point):</span><br><span class="line">    z:int =0</span><br><span class="line"></span><br><span class="line">ppp = ThirdPonit(1,3,4)</span><br><span class="line">print(ppp)   # ThirdPonit(x=2, y=3, z=4)</span><br></pre></td></tr></table></figure>
<p><strong>super</strong><br><figure class="highlight plain"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br></pre></td><td class="code"><pre><span class="line">from dataclasses import dataclass</span><br><span class="line"></span><br><span class="line">@dataclass</span><br><span class="line">class Point:</span><br><span class="line">    x:int = 0</span><br><span class="line">    y:int = 0</span><br><span class="line"></span><br><span class="line">    def __post_init__(self):</span><br><span class="line">        self.x += 1</span><br><span class="line"></span><br><span class="line">@dataclass</span><br><span class="line">class ThirdPonit(Point):</span><br><span class="line">    z:int =0</span><br><span class="line"></span><br><span class="line">    def __post_init__(self):</span><br><span class="line">        super().__post_init__()  # 调用 父类的__post_init__()</span><br><span class="line">        self.x += 10</span><br><span class="line"></span><br><span class="line">ppp = ThirdPonit(1,3,4)</span><br><span class="line">print(ppp)   # ThirdPonit(x=12, y=3, z=4)</span><br></pre></td></tr></table></figure></p>
<h2 id="复合初始化"><a href="#复合初始化" class="headerlink" title="复合初始化"></a>复合初始化</h2><figure class="highlight plain"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br></pre></td><td class="code"><pre><span class="line">import random</span><br><span class="line">from dataclasses import dataclass</span><br><span class="line"></span><br><span class="line">def get_random_marks():</span><br><span class="line">    return [random.randint(1,10) for _ in range(5)]</span><br><span class="line"></span><br><span class="line">@dataclass</span><br><span class="line">class Student:</span><br><span class="line">    marks:list = list</span><br><span class="line"></span><br><span class="line">    def __post_init__(self):  # 额外的工作</span><br><span class="line">        self.marks = get_random_marks()</span><br><span class="line"></span><br><span class="line">a = Student()</span><br><span class="line">print(a)  # Student(marks=[2, 9, 8, 8, 2])</span><br><span class="line">print(a.marks)  # [2, 9, 8, 8, 2]</span><br></pre></td></tr></table></figure>
<p><strong>修改</strong><br><figure class="highlight plain"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br></pre></td><td class="code"><pre><span class="line">import random</span><br><span class="line">from dataclasses import dataclass, field</span><br><span class="line"></span><br><span class="line">def get_random_marks():</span><br><span class="line">    return [random.randint(1,10) for _ in range(5)]</span><br><span class="line"></span><br><span class="line">@dataclass</span><br><span class="line">class Student:</span><br><span class="line">    marks:int = field(default_factory= get_random_marks)  # int 不建议，建议使用数据类型</span><br><span class="line">    # default_factory ：如果在创建对象时没赋值，则使用该方法初始化该字段 （必须是可以调用的无参数方法）</span><br><span class="line">    # 使用 get_random_marks 方法 初始化 marks</span><br><span class="line">    </span><br><span class="line"></span><br><span class="line">a = Student()</span><br><span class="line">print(a)  # Student(marks=[7, 2, 4, 7, 4])</span><br><span class="line">print(a.marks)  # [7, 2, 4, 7, 4]</span><br><span class="line">print(type(a.marks))  # &lt;class &apos;list&apos;&gt;</span><br><span class="line">b = Student(&apos;b&apos;)  # 传参则不影响</span><br><span class="line">print(b)  # Student(marks=&apos;b&apos;)</span><br><span class="line">print(b.marks)  # b</span><br><span class="line">print(type(b.marks))  # &lt;class &apos;str&apos;&gt;</span><br></pre></td></tr></table></figure></p>
<h3 id="filed-更多操作"><a href="#filed-更多操作" class="headerlink" title="filed 更多操作"></a>filed 更多操作</h3><figure class="highlight plain"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br></pre></td><td class="code"><pre><span class="line">from dataclasses import dataclass, field</span><br><span class="line"></span><br><span class="line">@dataclass(order=1)</span><br><span class="line">class Number:</span><br><span class="line">    number:int = field(compare= False,repr= False)  # number 不进行比较,不打印</span><br><span class="line">    val:int</span><br><span class="line">    verified:1 = field(default=0,init=0) # 默认为 1，不进行初始化</span><br><span class="line"></span><br><span class="line">a = Number(3,4)</span><br><span class="line">b = Number(4,3)</span><br><span class="line">print(a &lt; b) # False</span><br><span class="line">print(a) # Number(val=4, verified=0)</span><br><span class="line">print(b) # Number(val=3, verified=0)</span><br><span class="line">b.verified = 1</span><br><span class="line">print(b) # Number(val=3, verified=1)</span><br></pre></td></tr></table></figure>

      
    </div>
    
    
    

    

    

    

    <footer class="post-footer">
      

      
      
      

      
        <div class="post-nav">
          <div class="post-nav-next post-nav-item">
            
              <a href="/python练习/迭代对象，迭代器，生成器/" rel="next" title="迭代对象，迭代器，生成器">
                <i class="fa fa-chevron-left"></i> 迭代对象，迭代器，生成器
              </a>
            
          </div>

          <span class="post-nav-divider"></span>

          <div class="post-nav-prev post-nav-item">
            
              <a href="/linux学习/计算机组成原理/" rel="prev" title="个人计算机">
                个人计算机 <i class="fa fa-chevron-right"></i>
              </a>
            
          </div>
        </div>
      

      
      
    </footer>
  </div>
  
  
  
  </article>



    <div class="post-spread">
      
    </div>
  </div>


          </div>
          


          

  



        </div>
        
          
  
  <div class="sidebar-toggle">
    <div class="sidebar-toggle-line-wrap">
      <span class="sidebar-toggle-line sidebar-toggle-line-first"></span>
      <span class="sidebar-toggle-line sidebar-toggle-line-middle"></span>
      <span class="sidebar-toggle-line sidebar-toggle-line-last"></span>
    </div>
  </div>

  <aside id="sidebar" class="sidebar">
    
    <div class="sidebar-inner">

      

      
        <ul class="sidebar-nav motion-element">
          <li class="sidebar-nav-toc sidebar-nav-active" data-target="post-toc-wrap">
            文章目录
          </li>
          <li class="sidebar-nav-overview" data-target="site-overview-wrap">
            站点概览
          </li>
        </ul>
      

      <section class="site-overview-wrap sidebar-panel">
        <div class="site-overview">
          <div class="site-author motion-element" itemprop="author" itemscope="" itemtype="http://schema.org/Person">
            
              <img class="site-author-image" itemprop="image" src="/images/avatar.png" alt="WeiLai">
            
              <p class="site-author-name" itemprop="name">WeiLai</p>
              <p class="site-description motion-element" itemprop="description">好学近乎知，力行近乎仁，知耻近乎勇</p>
          </div>

          <nav class="site-state motion-element">

            
              <div class="site-state-item site-state-posts">
              
                <a href="/archives/">
              
                  <span class="site-state-item-count">132</span>
                  <span class="site-state-item-name">日志</span>
                </a>
              </div>
            

            
              
              
              <div class="site-state-item site-state-categories">
                <a href="/categories/index.html">
                  <span class="site-state-item-count">15</span>
                  <span class="site-state-item-name">分类</span>
                </a>
              </div>
            

            
              
              
              <div class="site-state-item site-state-tags">
                
                  <span class="site-state-item-count">2</span>
                  <span class="site-state-item-name">标签</span>
                
              </div>
            

          </nav>

          

          
            <div class="links-of-author motion-element">
                
                  <span class="links-of-author-item">
                    <a href="https://github.com/itswl" target="_blank" title="GitHub">
                      
                        <i class="fa fa-fw fa-github"></i>GitHub</a>
                  </span>
                
                  <span class="links-of-author-item">
                    <a href="mailto:imwl@live.com" target="_blank" title="E-Mail">
                      
                        <i class="fa fa-fw fa-envelope"></i>E-Mail</a>
                  </span>
                
                  <span class="links-of-author-item">
                    <a href="https://www.jianshu.com/u/6aa4c1b2a4a4" target="_blank" title="简书">
                      
                        <i class="fa fa-fw fa-book"></i>简书</a>
                  </span>
                
                  <span class="links-of-author-item">
                    <a href="https://www.facebook.com/profile.php?id=100021764796181" target="_blank" title="Facebook">
                      
                        <i class="fa fa-fw fa-facebook"></i>Facebook</a>
                  </span>
                
            </div>
          

          
          

          
          

          

        </div>
      </section>

      
      <!--noindex-->
        <section class="post-toc-wrap motion-element sidebar-panel sidebar-panel-active">
          <div class="post-toc">

            
              
            

            
              <div class="post-toc-content"><ol class="nav"><li class="nav-item nav-level-1"><a class="nav-link" href="#待解决"><span class="nav-number">1.</span> <span class="nav-text">待解决</span></a><ol class="nav-child"><li class="nav-item nav-level-2"><a class="nav-link" href="#基础"><span class="nav-number">1.1.</span> <span class="nav-text">基础</span></a></li><li class="nav-item nav-level-2"><a class="nav-link" href="#使用第三方插件修改一下"><span class="nav-number">1.2.</span> <span class="nav-text">使用第三方插件修改一下</span></a></li><li class="nav-item nav-level-2"><a class="nav-link" href="#声明和比较"><span class="nav-number">1.3.</span> <span class="nav-text">声明和比较</span></a></li><li class="nav-item nav-level-2"><a class="nav-link" href="#使用python3-7-的内置库"><span class="nav-number">1.4.</span> <span class="nav-text">使用python3.7 的内置库</span></a><ol class="nav-child"><li class="nav-item nav-level-3"><a class="nav-link" href="#有关继承"><span class="nav-number">1.4.1.</span> <span class="nav-text">有关继承</span></a></li></ol></li><li class="nav-item nav-level-2"><a class="nav-link" href="#复合初始化"><span class="nav-number">1.5.</span> <span class="nav-text">复合初始化</span></a><ol class="nav-child"><li class="nav-item nav-level-3"><a class="nav-link" href="#filed-更多操作"><span class="nav-number">1.5.1.</span> <span class="nav-text">filed 更多操作</span></a></li></ol></li></ol></li></ol></div>
            

          </div>
        </section>
      <!--/noindex-->
      

      

    </div>
  </aside>


        
      </div>
    </main>

    <footer id="footer" class="footer">
      <div class="footer-inner">
        <div class="copyright">&copy; <span itemprop="copyrightYear">2019</span>
  <span class="with-love">
    <i class="fa fa-user"></i>
  </span>
  <span class="author" itemprop="copyrightHolder">WeiLai</span>

  
</div>


  <!--<div class="powered-by">由 <a class="theme-link" target="_blank" href="https://hexo.io">Hexo</a> 强力驱动</div>



  <span class="post-meta-divider">|</span>



  <div class="theme-info">主题 &mdash; <a class="theme-link" target="_blank" href="https://github.com/iissnan/hexo-theme-next">NexT.Pisces</a> v5.1.4</div>

-->



        







        
      </div>
    </footer>

    
      <div class="back-to-top">
        <i class="fa fa-arrow-up"></i>
        
      </div>
    

    

  </div>

  

<script type="text/javascript">
  if (Object.prototype.toString.call(window.Promise) !== '[object Function]') {
    window.Promise = null;
  }
</script>









  












  
  
    <script type="text/javascript" src="/lib/jquery/index.js?v=2.1.3"></script>
  

  
  
    <script type="text/javascript" src="/lib/fastclick/lib/fastclick.min.js?v=1.0.6"></script>
  

  
  
    <script type="text/javascript" src="/lib/jquery_lazyload/jquery.lazyload.js?v=1.9.7"></script>
  

  
  
    <script type="text/javascript" src="/lib/velocity/velocity.min.js?v=1.2.1"></script>
  

  
  
    <script type="text/javascript" src="/lib/velocity/velocity.ui.min.js?v=1.2.1"></script>
  

  
  
    <script type="text/javascript" src="/lib/fancybox/source/jquery.fancybox.pack.js?v=2.1.5"></script>
  


  


  <script type="text/javascript" src="/js/src/utils.js?v=5.1.4"></script>

  <script type="text/javascript" src="/js/src/motion.js?v=5.1.4"></script>



  
  


  <script type="text/javascript" src="/js/src/affix.js?v=5.1.4"></script>

  <script type="text/javascript" src="/js/src/schemes/pisces.js?v=5.1.4"></script>



  
  <script type="text/javascript" src="/js/src/scrollspy.js?v=5.1.4"></script>
<script type="text/javascript" src="/js/src/post-details.js?v=5.1.4"></script>



  


  <script type="text/javascript" src="/js/src/bootstrap.js?v=5.1.4"></script>



  


  




	





  





  












  

  <script type="text/javascript">
    // Popup Window;
    var isfetched = false;
    var isXml = true;
    // Search DB path;
    var search_path = "search.xml";
    if (search_path.length === 0) {
      search_path = "search.xml";
    } else if (/json$/i.test(search_path)) {
      isXml = false;
    }
    var path = "/" + search_path;
    // monitor main search box;

    var onPopupClose = function (e) {
      $('.popup').hide();
      $('#local-search-input').val('');
      $('.search-result-list').remove();
      $('#no-result').remove();
      $(".local-search-pop-overlay").remove();
      $('body').css('overflow', '');
    }

    function proceedsearch() {
      $("body")
        .append('<div class="search-popup-overlay local-search-pop-overlay"></div>')
        .css('overflow', 'hidden');
      $('.search-popup-overlay').click(onPopupClose);
      $('.popup').toggle();
      var $localSearchInput = $('#local-search-input');
      $localSearchInput.attr("autocapitalize", "none");
      $localSearchInput.attr("autocorrect", "off");
      $localSearchInput.focus();
    }

    // search function;
    var searchFunc = function(path, search_id, content_id) {
      'use strict';

      // start loading animation
      $("body")
        .append('<div class="search-popup-overlay local-search-pop-overlay">' +
          '<div id="search-loading-icon">' +
          '<i class="fa fa-spinner fa-pulse fa-5x fa-fw"></i>' +
          '</div>' +
          '</div>')
        .css('overflow', 'hidden');
      $("#search-loading-icon").css('margin', '20% auto 0 auto').css('text-align', 'center');

      $.ajax({
        url: path,
        dataType: isXml ? "xml" : "json",
        async: true,
        success: function(res) {
          // get the contents from search data
          isfetched = true;
          $('.popup').detach().appendTo('.header-inner');
          var datas = isXml ? $("entry", res).map(function() {
            return {
              title: $("title", this).text(),
              content: $("content",this).text(),
              url: $("url" , this).text()
            };
          }).get() : res;
          var input = document.getElementById(search_id);
          var resultContent = document.getElementById(content_id);
          var inputEventFunction = function() {
            var searchText = input.value.trim().toLowerCase();
            var keywords = searchText.split(/[\s\-]+/);
            if (keywords.length > 1) {
              keywords.push(searchText);
            }
            var resultItems = [];
            if (searchText.length > 0) {
              // perform local searching
              datas.forEach(function(data) {
                var isMatch = false;
                var hitCount = 0;
                var searchTextCount = 0;
                var title = data.title.trim();
                var titleInLowerCase = title.toLowerCase();
                var content = data.content.trim().replace(/<[^>]+>/g,"");
                var contentInLowerCase = content.toLowerCase();
                var articleUrl = decodeURIComponent(data.url);
                var indexOfTitle = [];
                var indexOfContent = [];
                // only match articles with not empty titles
                if(title != '') {
                  keywords.forEach(function(keyword) {
                    function getIndexByWord(word, text, caseSensitive) {
                      var wordLen = word.length;
                      if (wordLen === 0) {
                        return [];
                      }
                      var startPosition = 0, position = [], index = [];
                      if (!caseSensitive) {
                        text = text.toLowerCase();
                        word = word.toLowerCase();
                      }
                      while ((position = text.indexOf(word, startPosition)) > -1) {
                        index.push({position: position, word: word});
                        startPosition = position + wordLen;
                      }
                      return index;
                    }

                    indexOfTitle = indexOfTitle.concat(getIndexByWord(keyword, titleInLowerCase, false));
                    indexOfContent = indexOfContent.concat(getIndexByWord(keyword, contentInLowerCase, false));
                  });
                  if (indexOfTitle.length > 0 || indexOfContent.length > 0) {
                    isMatch = true;
                    hitCount = indexOfTitle.length + indexOfContent.length;
                  }
                }

                // show search results

                if (isMatch) {
                  // sort index by position of keyword

                  [indexOfTitle, indexOfContent].forEach(function (index) {
                    index.sort(function (itemLeft, itemRight) {
                      if (itemRight.position !== itemLeft.position) {
                        return itemRight.position - itemLeft.position;
                      } else {
                        return itemLeft.word.length - itemRight.word.length;
                      }
                    });
                  });

                  // merge hits into slices

                  function mergeIntoSlice(text, start, end, index) {
                    var item = index[index.length - 1];
                    var position = item.position;
                    var word = item.word;
                    var hits = [];
                    var searchTextCountInSlice = 0;
                    while (position + word.length <= end && index.length != 0) {
                      if (word === searchText) {
                        searchTextCountInSlice++;
                      }
                      hits.push({position: position, length: word.length});
                      var wordEnd = position + word.length;

                      // move to next position of hit

                      index.pop();
                      while (index.length != 0) {
                        item = index[index.length - 1];
                        position = item.position;
                        word = item.word;
                        if (wordEnd > position) {
                          index.pop();
                        } else {
                          break;
                        }
                      }
                    }
                    searchTextCount += searchTextCountInSlice;
                    return {
                      hits: hits,
                      start: start,
                      end: end,
                      searchTextCount: searchTextCountInSlice
                    };
                  }

                  var slicesOfTitle = [];
                  if (indexOfTitle.length != 0) {
                    slicesOfTitle.push(mergeIntoSlice(title, 0, title.length, indexOfTitle));
                  }

                  var slicesOfContent = [];
                  while (indexOfContent.length != 0) {
                    var item = indexOfContent[indexOfContent.length - 1];
                    var position = item.position;
                    var word = item.word;
                    // cut out 100 characters
                    var start = position - 20;
                    var end = position + 80;
                    if(start < 0){
                      start = 0;
                    }
                    if (end < position + word.length) {
                      end = position + word.length;
                    }
                    if(end > content.length){
                      end = content.length;
                    }
                    slicesOfContent.push(mergeIntoSlice(content, start, end, indexOfContent));
                  }

                  // sort slices in content by search text's count and hits' count

                  slicesOfContent.sort(function (sliceLeft, sliceRight) {
                    if (sliceLeft.searchTextCount !== sliceRight.searchTextCount) {
                      return sliceRight.searchTextCount - sliceLeft.searchTextCount;
                    } else if (sliceLeft.hits.length !== sliceRight.hits.length) {
                      return sliceRight.hits.length - sliceLeft.hits.length;
                    } else {
                      return sliceLeft.start - sliceRight.start;
                    }
                  });

                  // select top N slices in content

                  var upperBound = parseInt('1');
                  if (upperBound >= 0) {
                    slicesOfContent = slicesOfContent.slice(0, upperBound);
                  }

                  // highlight title and content

                  function highlightKeyword(text, slice) {
                    var result = '';
                    var prevEnd = slice.start;
                    slice.hits.forEach(function (hit) {
                      result += text.substring(prevEnd, hit.position);
                      var end = hit.position + hit.length;
                      result += '<b class="search-keyword">' + text.substring(hit.position, end) + '</b>';
                      prevEnd = end;
                    });
                    result += text.substring(prevEnd, slice.end);
                    return result;
                  }

                  var resultItem = '';

                  if (slicesOfTitle.length != 0) {
                    resultItem += "<li><a href='" + articleUrl + "' class='search-result-title'>" + highlightKeyword(title, slicesOfTitle[0]) + "</a>";
                  } else {
                    resultItem += "<li><a href='" + articleUrl + "' class='search-result-title'>" + title + "</a>";
                  }

                  slicesOfContent.forEach(function (slice) {
                    resultItem += "<a href='" + articleUrl + "'>" +
                      "<p class=\"search-result\">" + highlightKeyword(content, slice) +
                      "...</p>" + "</a>";
                  });

                  resultItem += "</li>";
                  resultItems.push({
                    item: resultItem,
                    searchTextCount: searchTextCount,
                    hitCount: hitCount,
                    id: resultItems.length
                  });
                }
              })
            };
            if (keywords.length === 1 && keywords[0] === "") {
              resultContent.innerHTML = '<div id="no-result"><i class="fa fa-search fa-5x" /></div>'
            } else if (resultItems.length === 0) {
              resultContent.innerHTML = '<div id="no-result"><i class="fa fa-frown-o fa-5x" /></div>'
            } else {
              resultItems.sort(function (resultLeft, resultRight) {
                if (resultLeft.searchTextCount !== resultRight.searchTextCount) {
                  return resultRight.searchTextCount - resultLeft.searchTextCount;
                } else if (resultLeft.hitCount !== resultRight.hitCount) {
                  return resultRight.hitCount - resultLeft.hitCount;
                } else {
                  return resultRight.id - resultLeft.id;
                }
              });
              var searchResultList = '<ul class=\"search-result-list\">';
              resultItems.forEach(function (result) {
                searchResultList += result.item;
              })
              searchResultList += "</ul>";
              resultContent.innerHTML = searchResultList;
            }
          }

          if ('auto' === 'auto') {
            input.addEventListener('input', inputEventFunction);
          } else {
            $('.search-icon').click(inputEventFunction);
            input.addEventListener('keypress', function (event) {
              if (event.keyCode === 13) {
                inputEventFunction();
              }
            });
          }

          // remove loading animation
          $(".local-search-pop-overlay").remove();
          $('body').css('overflow', '');

          proceedsearch();
        }
      });
    }

    // handle and trigger popup window;
    $('.popup-trigger').click(function(e) {
      e.stopPropagation();
      if (isfetched === false) {
        searchFunc(path, 'local-search-input', 'local-search-result');
      } else {
        proceedsearch();
      };
    });

    $('.popup-btn-close').click(onPopupClose);
    $('.popup').click(function(e){
      e.stopPropagation();
    });
    $(document).on('keyup', function (event) {
      var shouldDismissSearchPopup = event.which === 27 &&
        $('.search-popup').is(':visible');
      if (shouldDismissSearchPopup) {
        onPopupClose();
      }
    });
  </script>





  

  

  
<script>
(function(){
    var bp = document.createElement('script');
    var curProtocol = window.location.protocol.split(':')[0];
    if (curProtocol === 'https') {
        bp.src = 'https://zz.bdstatic.com/linksubmit/push.js';        
    }
    else {
        bp.src = 'http://push.zhanzhang.baidu.com/push.js';
    }
    var s = document.getElementsByTagName("script")[0];
    s.parentNode.insertBefore(bp, s);
})();
</script>


  
  

  

  

  

  
</body>
</html>
